The invention relates generally to improvements in apparatus for the production of continuous strand fiber glass mats and more particularly to an apparatus for diffusing or widening the band width of strands from a pull wheel in a mat forming apparatus.
The production of continuous strand mats has reached a high state of development. For example, U.S. Pat. No. 3,599,848, granted Aug. 17, 1971, teaches a method and apparatus for distributing strands on a conveyor mat using aerodynamically configured nozzles and air foil members. The distribution of the strands on a collecting surface may be adjusted by controlling the flow of fluid through the nozzles or air foils.
U.S. Pat. No. 3,936,558, granted Feb. 3, 1976, relates to the production of a continuous fiber mat. In this patent, a product which includes at least two layers of strands of continuous glass filaments, is disclosed. In one layer, the filaments of the strands are arranged to form a mesh size which traps binder particles therein. The strands in another layer form a larger mesh size.
Significant attention has been accorded the subject of diffusing the filaments of the strands. In U.S. Pat. No. 4,515,613, granted May 7, 1985, the strands pass through a nozzle where they contact a high velocity planar gaseous stream. The gaseous stream imparts energy to the strands and separates them, significantly widening the band width of the plural strands.
A similar apparatus utilizing a high velocity gaseous stream is disclosed in U.S. Pat. No. 4,600,423 granted July 15, 1986. Once again, the strands of filaments pass through a nozzle where they contact a high velocity gaseous stream. The turbulence created by the stream separates the strands and individual filaments and broadens the band width of the strands as they exit the nozzle and fall upon the collecting conveyor.
The foregoing devices may be characterized as active strand diffusers in that external energy in the form of a high velocity gaseous stream is supplied to the nozzle. U.S. Pat. No. 3,265,482, granted Aug. 9, 1966, discloses a passive deflector. In this patent, a cylindrical deflector fabricated of screen is disposed for oscillation with the spoke wheel within the pull wheel such that the relative angles between the deflector and the spoke wheel remain constant during oscillation of these components about the pull wheel. The porous nature of the screen deflector is said to be beneficial as it lessens the turbulence of air occurring at the surface of the deflector which ordinarily causes an undesirable irregularity in the path of the strands.
As demands for increased production have risen, every aspect of continuous strand mat fabrication apparatus has undergone scrutiny. An area that has continued to undergo such scrutiny are the means and method of dispersing the individual strands from a pull wheel to effectively extend the area over which the fibers are dispersed on the conveyor and thus improve production throughput. The present invention relates to such improvements.